In the conventional apparatus of assembling stay-in-place cement board (also known as concrete board) forms for wall units the cement boards, that are typically in the form of 4 feet by 8 feet by half inch-thick fiber-glass reinforced cement board panels, are lifted into place and held using flexible form ties. Consistent spacing between the cement boards is maintained by using plates or tubes attached to or fitted around the form ties. U.S. Pat. No. 4,598,519 entitled "Composite Concrete Walls Having Tie & Form Spacing" and U.S. patent application Ser. No. 08/066,675 entitled "Building Wall & Method of Constructing Same" are examples of this method. Blocks placed around the top and sides of the concrete panels can also be used as taught in U.S. Pat. No. 4,938,449 entitled "Tie for Concrete Forms." Foamed concrete is then pumped into the space between the boards. After the concrete has gained strength, the ends of the form ties are trimmed flush with the cement board forms. Limitations of these existing apparatus include: i) The form ties must be threaded through holes in one wall panel and then through corresponding holes in the second wall panel. Generally both panels must be braced partly upright to place the form ties. The forms that will be filled with concrete to make wall sections generally have the wall panels 5.5 inches apart to make a 6.5-inch thick wall. The panels have to be braced partly upright and far enough apart for a crew member to move between them. Thus long form ties are needed although when assembled the wall panels will be only 5.5 inches apart. ii) All of the form ties must be in position before any of the form ties are tightened or secured by bracing. There is no easy way to add form ties after the form is assembled; and iii) Until the fasteners on the form ties are tightened down, the form ties do not support the wall panels.
U.S. Pat. No. 2,076,473 entitled "Building Construction" teaches of a corrugated spacer construction in a composite form construction where the spacer assembly has a boss structure that inserts into a corresponding depression in the wall forms. Limitations of this type of spacer-tie assembly are: i) The complexity of the wall forms and the spacer construction; ii) The load from the fluid concrete is transferred to the spacer which can be deformed by the outward pressure exerted by the concrete mixture prior to setting; iii) The connection of the spacer to the wall panel is by means of a concave disk that must be flattened in a pre-drilled hole that partly penetrates the wall panel, thus producing a relatively weak attachment to the panel; and iv) The holes in the wall panels are drilled to half-depth and must be precisely aligned with respect to the spacer if the wall panel is to be properly attached to the spacer.
These prior form-tie rod assemblies generally require excessive time to construct and require complex-individuated component members that entail excessive expense. These problems are solved by the form-tie rod assembly of the instant invention.